Catalyst for ozone decomposition

Abstract

Coprecipitation of platinum, palladium, and manganese oxide on a suitable ceramic support gives an efficient catalyst for the decomposition of ozone at elevated temperatures. Activity is restored by exposure to air for periods of a few hours.

What is claimed is: 
     
       1. In an apparatus for reduction of ozone content of air intended for human respiration, a contact catalyst comprising refractory support means and coprecipitated platinum, palladium and maganese oxide in relative proportions by weight of 0.0024% to 0.47% Pt, 0.0038% to 0.75% Pd and 0.0023% to 0.96% MnO x  where x is 1.75 to 2.5. 
     
     
       2. Contact catalyst according to claim 1 wherein the body of the support is a honeycomb structure of cordierite coated with gamma-alumina. 
     
     
       3. Contact catalyst according to claim 2 wherein there is 1.7% gamma-alumina, 0.25% Pt, 0.11% Pd, and 0.39% MnO x . 
     
     
       4. Process for producing a contact catalyst for decomposition of ozone present in air comprising (A) impregnating a catalyst support with a solution comprising 1. 0.05 to 10% chloroplatinic acid hexahydrate   2. 0.05 to 10% palladous chloride and   3. 0.06 to 25% manganous nitrate     (B) drying the impregnated catalyst support and   (C) heating the impregnated catalyst support in air at a temperature sufficient to reduce chloroplatinic acid to platinum metal and palladous chloride to palladium metal and to oxidize manganous nitrate to manganese oxide.